Electronic apparatus for programmed automatic playing of musical accompaniment systems

ABSTRACT

An electronic circuit or apparatus which, when properly combined with a keyboard electronic instrument of the button or similar type, allows automatic and programmable playing of musical accompaniments including basses, chords, arpeggio and scales, formed by notes and/or groups of notes played in periodical succession, all of which is correlated by a programmed rhythmical control.

United States Patent [191 Aliprandi ELECTRONIC APPARATUS FOR PROGRAMMED AUTOMATIC PLAYING OF MUSICAL ACCOMPANIMENT SYSTEMS TONE GENERATOR ACCOMPANIMENT KEYBOARD 1 Aug. 27, 1974 6/1971 Schwartz et al. 84/1.03 3,624,263 1 H1971 Uchiyama 84/l.03 3,646,242 2/1972 Okamoto 84/1.03 3,697,664 10/1972 Hiyama 84/|.l7 3,707,594 12/1972 lchikawa 84/1.03 3,708,602 1/1973 Hiyama 84/1.03 3,711,618 1/1973 Freeman 84/1.03 3,712,950 l/1973 Freeman 84/1.03 3,715,442 2/1973 Freeman 84/l.0l

Primary Examiner-Richard B. Wilkins on Assistant Examiner-Stanley J. Witkowski [57] ABSTRACT An electronic circuit or apparatus which, when properly combined with a keyboard electronic instrument of the button or similar type, allows automatic and programmable playing of musical accompaniments including basses, chords, arpeggio and scales, formed by notes and/or groups of notes played in periodical succession, all of which is correlated by a programmed rhythmical control.

7 Claims, 1 Drawing Figure TREBLE K EYBOARD POWER AMPLIFIER TREBLE FILTERS $PEAKER j is L 7 14 l- 27 L X 1 15 CHORD FILTERS ARPEGGIO ON-OFF i SELECTOR 1 2.

] SELECTED NOISE GENERATORS CYCLICAL FFE PROGRAMMER ARPEGGIO ELECTRONIC APPARATUS FOR PROGRAMMED AUTOMATIC PLAYING OF MUSICAL ACCOMPANIMENT SYSTEMS BACKGROUND OF THE INVENTION A musician playing an electronic musical keyboard instrument produces various types of accompaniment. Assuming that the right hand plays the melody of a musical composition, the left hand is used to play the accompaniment including notes or groups of notes such as chords, and the pedalboard is used to play the basses complementary to these notes or groups of notes. This system is exclusively manual and requires skill to coordinate all the movements of the hands and feet which are necessary for the correct performance of a musical piece.

For example, it is difficult for a musician with average technical musical ability to rhythmically alternate the basses of the pedalboard with a chord especially if the chord is also rhythmical played and it is almost impossible to add to the above musical accompaniment an arpeggio.

In some prior art systems automatic rhythms such as brush, bass or drum are combined with the electronic instrument to obtain a variety of sounds. However, although such sounds enrich the performance of the musician, they do not simplify the problem of coordinating the movements of the hands and feet.

Other prior art systems simplify the problem by eliminating the use of the feet by using preferential circuits to select a treble note and a bass note. This selection allows two notes of the same frequency range of the pedalboard to be properly alternated and coordinated with the chord. The notes are played through gates which in turn are controlled by a cyclical programmer.

However, such systemsdo not permit obtaining bass effects of more than two different notes, nor do they permit obtaining either arpeggios or scales covering the whole frequency range of the electronic instrument.

BRIEF DESCRIPTION OF THE INVENTION The present invention makes use of one of the numerous and wellknown systems of automatic cycle timers which controls the operation of appropriate gates through which sounds are sent to the output of an amplification circuit. These sounds are of different origins, made up of noises selected from frequencies or groups of frequencies corresponding to notes of the instruments scale.

A first group of gate controls a group of selected noise, whose combination according to programmes established by the designer, provide rhythm accompaniments such as Waltz, Bossanova, March or others.

A second group of gates controls the output production of single notes, groups of notes and the octave in accordance with the preset programme.

The above will be more fully explained by the following description taken in conjunction with the accompanying drawing illustrating a block diagram of this invention which is combined with an electronic musical instrument.

In practice, a musician using an electronic musical instrument of the keyboard, button or similar type, and including circuits of the type of the present invention, has the possibility of playing at the same time, a simple chord on the accompaniment manual, for instance C-E-G, either continuously or rhythmically and at the same time the three single notes of the chord taken one at a time according to a predetermined sequence can be played over a range of four octaves, extendable to 5 octaves. This sequence, therefore, allows the musician to obtain either ascending and/or descending scales and/or 'arpeggios or octaves, by preferably using. the medium-treble area of the range of frequencies available. This sequence can also provide bass accomnized so as to have a musically valid combination.

Finally, utilizing circuits which can be realized in accordance with the concepts of the subject invention, the musician can have any number of notes used, not only three, to obtain effects similar to those described above.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawing the system of the present invention is shown in a block diagram since the detailed circuits are known to experts and since such circuits can be realized in different ways using either traditional or integrated components. The present invention is not related to each individual circuit but to the system as a whole.

Tone generators providing the signal sources are indicated at 10. Generally, in an organ or other electronic musical instrument they consist of twelve oscillators which supply the frequencies relative to the highest octave of the instrument and of twelve chains of many dividers each one formed by as many dividers as the frequencies necessitate to cover thewhole extension of the organ or other instrument. As per our example, the frequencies required for the accompaniment section of the keyboard 11 go from C, 1046 Hz, to G, 3136 Hz, while the frequencies sent to the treble section of the keyboard 12 can be as desired and depend upon the type of organ with which the circuits relative to this invention are combined. Keyboard 11 and 12 can be separate or aligned.

The signals selected on the treble keyboard 12 pass through the treble filters l3 and then are properly amplified by the power amplifier in the output unit 14 and come out of the loudspeaker 15. Since this invention is only concerned with possible accompaniments that can be obtained from the accompaniment section of the keyboard 11, any changes in the basic diagram of the treble section do not alter the present invention.

The accompaniment keyboard section 11 includes the following circuits: an output circuit 20 where contemporarily all the signals corresponding to all the keys played appear; a rectifier circuit included in the keyboard section 11 whose output is 19, driven by the same signal that appears at circuit 20, which at the output gives an S signal in DC whose use shall be seen further on; three perferential selection devices 16,17,18 such that whatever keys are played, their outputs are respectively, frequency fl, corresponding to the key depressed first from the left, f2 corresponding to the key depressed second from the left, and f3 corresponding to the key depressed first from the right.

These selection devices can be realized mechanically with a series of successive exchange contacts, or with electronic circuits as for example those indicated in U.S. Pat. No. 2,874,286 issued to Bode. Both solutions are, however, well known to electronic organ designers.

When one or more keys of the accompaniment section 11 are depressed, for example, C-E-G, at the output from the circuit 19 the S signal in DC. is obtained which triggers the cyclical programmer 21. The programmer 21 can be realized in one of the many well known ways, for example with a low frequency oscillator followed by a chain of dividers, whose outputs are decoded by means of a diode matrix. The outputs of a first matrix are then used by a second much more complex matrix to obtain programmed successions of pulses, which make up the outputs of the cyclical programmer. Using integrated circuits, the two aforementioned matrixes can be substituted by a read only memory, or all the programmer, excluding' the oscillator, can be substituted with an LSl circuit. One such embodiment can be realized by utilizing a pulse oscillator connected to a chain of five frequency dividers. The dividers can be made up of an integrated circuit TTL Dual 3+1 Flip Flop with clear, as for example type SN29722N produced by Texas instruments Incorporated. The output of the dividers are fed to a read only memory of the type TMS2700 produced by Texas instruments incorporated. Alternately, the programmer can be similar to the rhythm programmer described in U.S. Pat. No. 3,567,838.

Some of the cyclical progammer 21 outputs are used to control, according to prefixed rhythmic patterns, the selected noise generators 22 made up of the type of circuits which are frequently used in electronic musical instruments and for example of the type described in U.S. Pat. No. 3,520,984 to W. V. Machanian. The rhythmiecombination thus realized appears, through a manually operated output selector 23, at the amplifier l4 and from there to the loudspeaker 15.

The remaining outputs of the cyclical programmer 21, and specifically those indicated in the group 24 and identified individually by the letters A to P, are used to control the gates shown by acting on a lead control of each one. Obviously, the sequences of pulses that appear at the output of the programmer 21 have been fixed when designed and depend on the taste of the designer. The player has the possibility of choosing in time the sequence which he prefers out of those available on the programmer by operating manual controls which are part of the programmer itself 21.

Each one of the aforesaid gates, for example gate 25, is made up by well known circuits, as for example the SN 7400, produced by Texas Instruments Incorporated integrated circuit and derived circuit, which are part of the TTL family and has the particularity of allowing to pass to its output the information applied at its input, only when a certain DC. signal appears on the control lead. In the absence of the control signal, no information can pass through the gate. Another particularity of these gates is that their opening and closing times can be regulated as desired by the designer, therefore, the gate controlled signals acquire extremely variable attack and decay characteristics.

By playing, as aforesaid, a C-E-G chord on the keyboard ll, the chord appearing at the output circuit passes directly to the filters 27 and then to the amplifier 14 when the switch 26 is closed. When the switch is open, the passing of the chord is conditioned by the gate 25 controlled on the A lead from the cyclical programmer 21. Frequencies fl, f2 and f3, which in the case of our example, if the chord is played in the normal order, coincides respectively with C-E-G, appears at the outputs of the preferential selection circuits l6, l7 and 18 respectively. The chord therefore appears at the inputs of gates 41, 42 and 43, which are alternatively energized by the programmer 21 according to determined rhythmic patterns. Therefore, at point 44 alternatively appear fl, f2 and f3, which are then divided by two, four and eight, by the chain of dividers 45, 46 and 47.

At point 48 appear alternatively f1, f2 and 13, at either their nominal frequencies or at a frequencies which are one, two or three octaves lower, according to the control program of gates 49, 50, 51 and 52. The signals thus selected bypass the divider 53 when the switch 54 is closed, or are again divided by two when the switch is open. Such signals, which according to the program with which gates 41, 42, 43, 49, 50, 51, 52 are controlled, make up an ascending or descending musical scale or arpeggio and enter through an ON/OFF control 55 into the filters 56 and from these pass to the amplifier l4 and then to the loudspeaker 15.

Frequencies f1 and f3 which appear at the outputs of the preferential selection circuits l6 and 18 respectively, appear at the inputs of the gates 28 and 29, which are alternatively energized by the programmer 21 according to predetermined patterns. At point 31, therefore, alternatively appear f1 and f3, which are then divided by two, four and eight by the chain of dividers 32, 33 and 34. At point 40 there appears fl and f3 alternatively, either at their nominal frequencies or at frequencies one, two or three octaves lower, according to the control program of the gates 30, 35, 36 and 37. The signals thus selected, which make up a bass accompaniment dependent on the program with which gates 28, 29, 30, 35, 36, 37 are controlled, enter through an ON/OF F control 38 into the filters 39 and from these pass to the amplifier 14 and thereon to the loudspeaker l5.

I claim:'

1. An electronic apparatus for use with an electronic musical instrument having signal generators for providing signal sources representative of the notes of the musical scale, at least an accompaniment keyboard for selecting note signals to be played, and output reproduction means for accoustically reproducing the notes, said apparatus comprising: at least four preferential selection circuit means (16,l7,18,20) coupled to said accompaniment keyboard and adapted to supply respectively at least the lowest note played, the note following the lowest note played, the highest note played and the mixture of all the notes played, when a group of any number of notes are played simultaneously on said accompaniment keyboard; chord gate means (25) receiving said mixture of all the notes played from the associated preferential selection means (20) and coupling it to the output reproduction means; a first group of gate means (41,42,43) each receiving respectively one of the outputs, other than said mixture of all the notes played, from the associated preferential selection circuit means (16,17,18): a first divider means (45,46,47) receiving the outputs from said first group of gates and dividing, in stages, the frequencies of the signals received, by successive powers of two; a second group of gate means, one of which (49) receives the output from stage of said first divider means, the outputs of said sec- 7 0nd group of gate means being coupled to the output reproduction means; and automatic cyclical program-' mer means (21) adapted to activate cyclically and automatically each of said gate means according to a present program to thereby pass the input to each gate means through the respective gate means.

2. Apparatus as in claim 1 and further comprising bypass switch means placed in parallel with said chord gate means such that when in a closed position the mixture of all the notes placed is sent directly to the output reproduction means.

3. Apparatus as in claim 1 and further comprising noise generator means providing rythmic signals whose output is coupled to said output reproduction means and being controlled by said cylical programmer means.

4. Apparatus as in claim 1 and further comprising rectifier circuit means driven by the signal corresponding to any note selected on the keyboard and providing a DC. signal, said DC. signal being used to activate said cylical programmer.

5. Apparatus as in claim 1 and further comprising a third group of gate means (28,29) each connected to respectively receive the highest note played and the lowest note played; second divider (32,33,34) means receiving the output from said third group of gate means and dividing, in stages, the frequencies of the signals received by successive powers of two; and a fourth group of gate means, one of which (30) receives the output from said third group of gate means and the others of which (35,36,37) each receive respectively an output from a stage of said second divider'mcans, the outputs of said fourth group of gate means being coupled to the output reproduction means.

6. Apparatus as in claim 5 and further comprising first manual switch'means (55) serially interconnected between the second group of gate means and the output reproduction means, and second manual switch means (38) serially interconnected between the fourth group of gate means and the output reproduction means.

7. Apparatus as in claim 1, wherein there are-N preferential selection circuits at the output of which appear (N-l) single notes and 1 chord selected in accordance with a preset arrangement. 

1. An electronic apparatus for use with an electronic musical instrument having signal generators for providing signal sources representative of the notes of the musical scale, at least an accompaniment keyboard for selecting note signals to be played, and output reproduction means for accoustically reproducing the notes, said apparatus comprising: at least four preferential selection circuit means (16,17,18,20) coupled to said accompaniment keyboard and adapted to supply respectively at least the lowest note played, the note following the lowest note played, the highest note played and the mixture of all the notes played, when a group of any number of notes are played simultaneously on said accompaniment keyboard; chord gate means (25) receiving said mixture of all the notes played from the associated preferential selection means (20) and coupling it to the output reproduction means; a first group of gate means (41,42,43) each receiving respectively one of the outputs, other than said mixture of all the notes played, from the associated preferential selection circuit means (16,17,18); a first divider means (45,46,47) receiving the outputs from said first group of gates and dividing, in stages, the frequencies of the signals received, by successive powers of two; a second group of gate means, one of which (49) receives the output from said first group of gate means and the others of which (50,51,52) each receive respectively an output from a stage of said first divider means, the outputs of said second group of gate means being coupled to the output reproduction means; and automatic cyclical programmer means (21) adapted to activate cyclically and automatically each of said gate means according to a present program to thereby pass the input to each gate means through the respective gate means.
 2. Apparatus as in claim 1 and further comprising bypass switch means placed in parallel with said chord gate means such that when in a closed position the mixture of all the notes placed is sent directly to the output reproduction means.
 3. Apparatus as in claim 1 and further comprising noise generator means providing rythmic signals whose output is coupled to said output reproduction means and being controlled by said cylical programmer means.
 4. Apparatus as in claim 1 and further comprising rectifier circuit means driven by the signal corresponding to any note selected on the keyboard and providing a D.C. signal, said D.C. signal being used to activate said cylical programmer.
 5. Apparatus as in claim 1 and further comprising a third group of gate means (28,29) each connected to respectively receive the highest note played and the lowest note played; second divider (32,33,34) means receiving the output from said third group of gate means and dividing, in stages, the frequencies of the signals received by successive powers of two; and a fourth group of gate means, one of which (30) receives the output from said third group of gate means and the others of which (35,36,37) each receive respectively an output from a stage of said second divider means, the outputs of said fourth group of gate means being coupled to the output reproduction means.
 6. Apparatus as in claim 5 and further comprising first manual switch means (55) serially interconnected between the second group of gate means and the output reproduction means, and second manual switch means (38) serially interconnected between the fourth group of gate means and the output reproduction means.
 7. Apparatus as in claim 1, wherein there are N preferential selection circuits at the output of which appear (N-1) single notes and 1 chord selected in accordance with a preset arrangement. 